Abstract A method to experimentally determine the components of complex thermal conductivity for thin polymer films has been developed. It is based on measuring the temperatures of both sides of a film in which a periodic temperature wave is excited. Formulas have been derived that relate the measured temperatures to the thermal conductivity components. Using this method, the frequency dependences

Abstract Using the methods of optically stimulated electron emission (OSEE) and ambient pressure photoemission spectroscopy (APS), the energy characteristics of carbyne-containing films on copper and silicon substrates have been studied. The average contact potential difference and the work function were determined, and the positions of the Fermi level for carbyne-containing films of various thicknesses

Abstract This work studies the formation of a charged equilibrium nanobubble on a smooth hydrophobic solid–water interface. Expressions are given for the change in the Gibbs energy of the system, taking into account the Kelvin capillary equation, the electrostatic energy of the electrical double layer at the bubble-water interface, and the surface energy. The graph of the Gibbs energy versus the nanobubble

Abstract The tensile strength of single-crystal sapphire specimens with c, a, d, r, n, s, g, and m crystallographic orientations (c-, a-, d-, r-, n-, s-, g-, and m-axis specimens) has been measured under shock compression in the stress range of 15–20 GPa. It has been found that the spall strength depends on shock direction and maximum compression strength. The spall strength is greatest, ~12–13 GPa

Abstract The resistivity of a number of dielectric–conductor composites as a function of applied voltage frequency has been studied for frequencies less than 1 MHz. It has been shown that the frequency dependence of the resistivity of dielectric–conductor composites containing a nonmagnetic material is low, being limited by the skin effect, whereas the resistivity of ferromagnet-containing composites

Abstract We report on the results of an analysis of the craze-formation center in plasma-modified polymers. It is shown that, as a result of plasma modification, oxidation, destruction, and joining processes occur in the polymer, which create conditions for the formation of craze centers and, hence, of crazes.

Abstract The energy distribution of atoms sputtered by ion bombardment of a solid has been calculated. The theoretical consideration relies on solving a set of two transport equations by the discrete streams method. It has been shown that, when the energy of sputtered atoms is low, their energy distribution is described by a universal function with a single constant. Its value grows with ionic weight

Abstract We have demonstrated that SiC mesastructures with gently sloping sidewalls form with the help of selective reactive ion etching (RIE) of silicon carbide through a photoresist mask (slanted walls are formed during simultaneous etching of SiC and the resistive mask with the edge in the shape of a sharp wedge). A simple geometrical model of etching predicts that the resultant slope of the mesastructure

Abstract Structural data and dependences of the film resistance on magnetic field strength R(H) are presented for Co–Gd and Al–Co–Gd alloy films obtained by vacuum sputtering. It has been found that amorphous Co55Gd45 films show ferromagnetism at room temperature. Singularities observed in the run of R(H) curves for Al84Co8Gd8 and Al92Co6Gd2 films are associated with magnetic ordering in the films

Abstract The temperature dependence of the conductivity of heat-treated polyvinyl chloride films containing conjugated double carbon–carbon bonds in the chain of its macromolecules and representing polyvinyl chloride–polyacetylene copolymers is studied. The samples with an above threshold concentration of conjugated carbon–carbon double bonds and associated charge carriers (π-electrons) exhibit changes

Abstract The dynamics of formation of a virtual cathode and the squeezed beam state (SBS) in a setup with a sublimiting relativistic electron beam under repeated input of the electron beam into the drift tube is studied by the particle-in-cell (PiC) simulation method. The physical characteristics of the SBS (the geometry as well as the electron concentration and temperature) are determined.

Abstract Magnesium powders with small additives of other metals are studied to determine the optimal conditions for hydrogenation and dehydrogenation for using them as a solid-state hydrogen storage for vehicles. An optimal composition with the weight formula Mg10Ni has been found. Only this composition is not subject to degradation of the reversible hydrogen capacity during cycling. It has been found

Abstract The motion of inertial particles in intense vortices with a vertical axis in the field of gravity has been analytically studied. In this problem, the nonlinear nature of the hydrodynamic resistance—its dependence on the modulus of the particle’s velocity relative to the medium—is essential. Different components of the movement interact with each other, since each of them affects the coefficient

Abstract We have established the conditions for the absence of Alfvén ion-cyclotron instability in the formation and subsequent acceleration of ion rings by collapsing cylindrical plasma liners.

Abstract A nonaberrational four-electrode lens for forming an ion beam for mass separators or spectrometers is described. A lens is a modification of a transaxial lens in which the circular gaps between the electrodes are replaced by elliptical gaps. The lens transforms an axially symmetrical beam into a ribbon-type beam. The lens parameters have been found using the phase diagram method. Using the

Abstract The ballistic resistance of a combined cermet material based on a high-hardness ceramic bound with an intermetallide on a high-strength metal substrate, (TiB2 + NiTi) + Ti, is compared with that of plates of steel, VT1-0 titanium alloy, and Al2O3 corundum ceramics upon an impact with a steel spherical impactor in the region of velocities of about 2500 m/s. Experimental studies of protective

Abstract A method for acceleration of electrons in a smooth cylindrical waveguide in the presence of the magnetic field of a solenoid is proposed. Electrons move in the waveguide along a helical trajectory that is shifted relative to the waveguide axis. Electrons are accelerated at the frequency of the cyclotron resonance along the waveguide axis by wave E01 or E02. It is shown that the acceleration

Abstract Dynamic breakdown of ammonium perchlorate single crystals is numerically simulated. A system of differential equations that describe processes in an equivalent circuit of a pulsed voltage oscillator, a kinetic equation of impact multiplication of electrons, and a heat-balance equation are simultaneously solved. The breakdown strength of ammonium perchlorate is calculated in the dynamic mode

Abstract Ferroelectric ceramic LixNa1 –xTayNb1 –yO3 (x = 0.17, y = 0–0.5) solid solutions with perovskite structure are synthesized for the first time by the thermobaric synthesis method (6 GPa, 1400–1800 K). The features of their structure and elastic properties are studied. It is shown that ceramic samples consist of grains of isomorphic shape and that faceting is inherent in the perovskite structure

Abstract The shear elastic properties of YBa2Cu3O7 –x high-temperature superconducting (HTSC) ceramics are studied near the superconducting transition at a temperature of 91.3 K and room temperature of 293 K. For the first time, a local increase in shear nonlinear acoustic parameter N in the region of the phase transition temperature was detected. Experimental studies of the linear and nonlinear elastic

Abstract Temperature dependences of the effective magnetic anisotropy field and ferromagnetic resonance linewidth in samples of isotropic and anisotropic hexaferrite SrFe11.2Al0.1Si0.15Ca0.15O19 and anisotropic hexaferrite BaFe10.4Al1.4Si0.15Mn0.1O19, obtained by ceramic technology with wet blanks pressed in the magnetic field of 10 kOe, were studied in the frequency range from 25 to 67 GHz. The studies

Abstract The formulated problem makes it possible to study the influence of magnetic forces on capillary instability of a ferrofluid jet with given physical characteristics in both weak and strong fields. The field intensity range includes values that correspond to the ferrofluid magnetization curve interval in which the curve reaches the value of saturation magnetization. The obtained growth rates

Abstract It is shown that a film consisting of the Mo–O, Mo–Ba–O, and Ba–O compounds is formed in the ion-implanted layer upon implantation of MoO3 with the Ba+ ions. Such a process leads to a sharp variation in the density of state of valence electrons, a decrease in work function eφ to 2.7 eV, a decrease in band gap Eg by a factor of about 1.5, and an increase in maximum coefficient of the secondary

Abstract Martensitic transformations of the TN-10 titanium-nickelide alloys doped with V, Nb, and Ag at a level of 1 at % are studied. It is shown that the alloying elements (Ag, Nb, and V) cause an increase in the elastic stress inside the B2-phase structure and the consequent increase in the start temperature of the direct martensite transformation. Vanadium significantly affects such a temperature

Abstract Dispersion characteristics of polariton excitations in a nonideal 1D lattice of micropores are studied versus concentrations of structural defects related to variations in the positions of the micropores that contain quantum dots in one sublattice. Such structural defects in the 1D sublattice array of micropores can be used to obtain desired changes of the energy structure of polariton excitations

Abstract We propose a series of experiments aimed at analysis of peculiarities and revealing general regularities in the penetrability of strikers made of a composite material based on tungsten + nickel + iron + cobalt alloy with an admixture of highly rigid refractory titanium–tungsten carbide particles in various initial conditions. In particular, we have analyzed the effect of the initial temperature

Abstract Elementary processes involved in low-pressure metalorganic compound hydride epitaxial growth of (Al, Ga, In)As heterostructures on misoriented GaAs(001) substrates have been studied using atomic force microscopy. It has been found that GaAs and AlGaAs epitaxial layers grow by a step–layered mechanism with the formation of microsteps. Pseudomorphic InGaAs/GaAs(001) layers also grow by this

Abstract The contact problem of a cylindrical indenter and gradient medium is considered with allowance for adhesion forces between surfaces of contacting bodies. An analytical solution of the problem is found for the case of a gradient medium with a power dependence of the elastic modulus on the normal coordinate. The case of incompressible media with a Poisson ratio of 1/2 is described in detail

Abstract We present a brief analytic review of position-sensitive detectors of thermal and cold neutrons based on a \(_{5}^{{10}}{\text{B}}\) thin-film converter. Most attention is paid to new approaches and technical solutions determining trends in development of this technique.

Abstract The phase composition and structure of oxide and hydrogen-reduced iron–ruthenium systems are studied using conversion and adsorption Mössbauer spectroscopy, as well as X-ray diffraction methods. In samples with metal concentration (mass %) 50Fe–50Ru after calcination in air at 773 and 973 K, nanosystems containing two phases with different degrees of dispersion are formed (α-Fe2O3 with an

Abstract A model of the electric field enhanced thermal (thermo-field) emission of electrons from the metal cathode substrate into a thin insulating film on its surface is developed. A system of equations for the cathode surface temperature in the arc discharge and the electric field strength in the film, providing the required discharge current density, is formulated. It is shown that existence of

Abstract A fast algorithm of calculating the passage of particles through a chain of bent single crystals is proposed based on the phenomenon of reflection of a relativistic-particle beam from crystal atomic planes. The results of calculating the passage of particles through a sequence of eight bent crystals are compared with the experimental data.

Abstract The formation of the cathode layer of a self-sustained high-pressure space discharge with preliminary ionization of a gas medium, excited by nano- and subnanosecond voltage pulses, is calculated. It is shown that, at pressures of ~1 atm, at the final stage of cathode layer formation, conditions for runaway electron generation are created. Runaway electrons from the electric field amplification

Abstract Finite-element method is used to calculate the force of electrostatic interaction of two conducting spheroidal objects with specified surface charges in the absence of external field.

Abstract A non-destructive method of scanning probe microscopy for simultaneous measurements of the surface topography and electric field (charge, potential) distribution is demonstrated. The surface is scanned by the tuning fork method, the interaction with the surface is carried out by the sharp edge of the silicon chip mounted on one of the prong of the quartz resonator. The detection of electric

Abstract The results of experimental studies on the development of scientific and technical foundations of a method to obtain cubic titanium carbide in plasma of a DC arc discharge initiated in air have been presented. According to X-ray diffractometry of powder materials obtained in a series of experiments, the dependences of phase composition of the product on the duration of synthesis have been

Abstract The anodic growth conditions of titania with a tubular structure are investigated. We propose a mechanism of anodic growth of tubular titania, which presupposes that electrochemical oxidation of titanium is predominantly confined to the bottom of pores in a barrier layer, i.e., where the anodic current density is higher, which causes a temperature rise in these regions. As the barrier layer

Abstract In high-pressure gas–jet Hartmann generators, the source of acoustic energy is kinetic energy of a gas jet by the supercritical ratio between the operation and ambient pressure. Under certain conditions, onflow of a supersonic jet to a resonator is accompanied by powerful self-sustained oscillations with irradiation of acoustic waves into the environment and resonator cavity. A model of a

Abstract The electrical performance of thermophotovoltaic converters with a flip-chip design based on p-InAsSbP/n-InAs/n-InAsSbP double heterostructures with the substrate completely or partially removed is examined. The influence of resistance of different parts of the structure on the spatial distribution of current density in the active region is revealed, and the conditions for maximizing the efficiency

Abstract Basic concepts of the autowave model of development of a localized plastic flow of solids of different natures are considered. It is shown that plastic deformation develops in a localized (at the macroscale level) way throughout the process. The form of the observed localization patterns is related to stages of strain hardening of the material. The patterns are projections of different modes